What is the lightest available armor if budget is not a factor?

[Mr Smith]

is 6.6lbs too heavy for them? suppose you add a back plate and it goes up to ~13lbs.

"Sarkar Defence Solutions" (their spelling, not mine) stand alone level 4 plate is capable of stopping multiple 30-06 M2 armor piercing rounds @ 50 yards.

 

[7SFCW4]

You may want to call the nice folks at BULLETPROOFME. Also, for field expedient protection, never discount common HDPE (kitchen cutting board) in one inch or thicker. A one inch sheet of HDPE will stop a 230 grain .45 at ten feet with plastic to spare. Often overlooked: Level 3A soft plate in kids backpack with or without HDPE layer, excellent coverage. Level 3A in your wife's purse. HDPE in the car doors, bottom of car. It does not stop common rifle rounds (unless you sandwich it with metal sheeting), but it does significantly slow rifle rounds down, especially if you use one inch of HDPE, 1/4 inch steel, 1/2 inch HDPE.

 

[Riot]

You may want to call the nice folks at BULLETPROOFME. Also, for field expedient protection, never discount common HDPE (kitchen cutting board) in one inch or thicker. A one inch sheet of HDPE will stop a 230 grain .45 at ten feet with plastic to spare. Often overlooked: Level 3A soft plate in kids backpack with or without HDPE layer, excellent coverage. Level 3A in your wife's purse. HDPE in the car doors, bottom of car. It does not stop common rifle rounds (unless you sandwich it with metal sheeting), but it does significantly slow rifle rounds down, especially if you use one inch of HDPE, 1/4 inch steel, 1/2 inch HDPE.

HDPE cutting boards vs .40 S&W - YouTube

*edit*

Just so we're clear, I've been on the DIY armor kick for a while now. I've tried a lot of different blends of polymers and ceramics...I've done a lot of research from The Poor Man's Bullet Proof Vest to letting other preppers do the leg work for me and try my own tests.

Want to know what I've concluded?

You can make your own plates out of common items found at home or in the store; however, you have to combine them properly with the right conditions, and even then they are heavy, time consuming, expensive to make and any process you screw up can cost you your life. There is no cure all and I've just decided to let the experts do what the experts are good at doing. Saying something is even "bullet resistant" takes a lot of faith in your product. There are so many variables (bullet type, grain, angle, speed, distance, etc.) that telling someone to simply grap a plastic cutting board to wrap them up with is asking for trouble.

Seriously guys, I've spent years on these projects. Vests...plates....all have come up short to the good stuff.

 

[7SFCW4]

Ah...YouTube...honesty on line, it is a good thing. I am holding in my hand a 1in thick piece of HDPE I purchased at the hardware scrap barrel. 230 grain USGI ball (slippery round) at ten feet, stopped COLD about 1/2 way thru (not exactly YouTube level of accuracy, and the chemical content from the scrap barrel is unknown to me). Mr Riot is quite correct, there is no substitute for the real thing. But in the off chance when the chips are down, I will take sheer will and knowledge over wishful thinking every time.

 

[chemist]

Kevlar (aromatic polyamide, or aramid) does not float - its density is 1.44 g/cc. When it's layered up with polyester or whatever to make a laminated soft armor, the resulting density is lower but still significantly greater than water.

The lowest density and highest modulus ballistic fiber is made from UHMWPE, which does indeed float. In a laminated form it's close to the density of water. Sold under trade names like SpectraShield and Dyneema, ballistic panels are available as either laminated tapes or laminated fabrics. The tapes are significantly thinner and lighter than the fabrics for the same protection in NIJ tests (like 30% thinner), but they can be less flexible, and some people think they aren't as good for protecting against contact-distance shots. (I disagree with those people.)

The very best passive composite armor is made from a mosaic of alumina plates over laminated tapes of UHMWPE. Remove the ceramic plates and the Level IV becomes Level III protection. Personal armor is usually thought of in terms of multiple-hit resistance, where vehicle armor is not. So for vehicles, the ceramic plates can be thin and sacrificial, intended to shatter and spread the incoming round so the Dyneema can do its job. It's unlikely that multiple rounds would hit a vehicle in exactly the same place, or that's the theory anyway.

It's expensive, but Dyneema works better than anything else for ballistic threats up to rifle fire. I'd choose laminated tapes.